88 lines
2.9 KiB
Python
88 lines
2.9 KiB
Python
import json
|
|
|
|
from smartcard.CardType import AnyCardType, ATRCardType
|
|
from smartcard.CardRequest import CardRequest
|
|
from smartcard.Exceptions import NoCardException, CardConnectionException
|
|
from smartcard.util import toHexString
|
|
|
|
from platypush.backend import Backend
|
|
from platypush.message.event.scard import SmartCardDetectedEvent, SmartCardRemovedEvent
|
|
|
|
|
|
class ScardBackend(Backend):
|
|
"""
|
|
Generic backend to read smart cards and NFC tags and trigger an event
|
|
whenever a device is detected.
|
|
|
|
Extend this backend to implement more advanced communication with custom
|
|
smart cards.
|
|
|
|
Triggers:
|
|
|
|
* :class:`platypush.message.event.scard.SmartCardDetectedEvent` when a smart card is detected
|
|
* :class:`platypush.message.event.scard.SmartCardRemovedEvent` when a smart card is removed
|
|
|
|
Requires:
|
|
|
|
* **pyscard** (``pip install pyscard``)
|
|
"""
|
|
|
|
def __init__(self, atr=None, *args, **kwargs):
|
|
"""
|
|
:param atr: If set, the backend will trigger events only for card(s) with the specified ATR(s). It can be either an ATR string (space-separated hex octects) or a list of ATR strings. Default: none (any card will be detected)
|
|
"""
|
|
|
|
super().__init__(*args, **kwargs)
|
|
self.ATRs = []
|
|
|
|
if atr:
|
|
if isinstance(atr, str):
|
|
self.ATRs = [atr]
|
|
elif isinstance(atr, list):
|
|
self.ATRs = atr
|
|
else:
|
|
raise RuntimeError("Unsupported ATR: \"{}\" - type: {}, " +
|
|
"supported types: string, list".format(
|
|
atr, type(atr)))
|
|
|
|
self.cardtype = ATRCardType( *[toBytes(atr) for atr in self.ATRs] )
|
|
else:
|
|
self.cardtype = AnyCardType()
|
|
|
|
|
|
def run(self):
|
|
super().run()
|
|
|
|
self.logger.info('Initialized smart card reader backend - ATR filter: {}'.
|
|
format(self.ATRs))
|
|
|
|
prev_atr = None
|
|
reader = None
|
|
|
|
while not self.should_stop():
|
|
try:
|
|
cardrequest = CardRequest(timeout=None, cardType=self.cardtype)
|
|
cardservice = cardrequest.waitforcard()
|
|
cardservice.connection.connect()
|
|
|
|
reader = cardservice.connection.getReader()
|
|
atr = toHexString(cardservice.connection.getATR())
|
|
|
|
if atr != prev_atr:
|
|
self.logger.info('Smart card detected on reader {}, ATR: {}'.
|
|
format(reader, atr))
|
|
|
|
self.bus.post(SmartCardDetectedEvent(atr=atr, reader=reader))
|
|
prev_atr = atr
|
|
except Exception as e:
|
|
if isinstance(e, NoCardException) or isinstance(e, CardConnectionException):
|
|
self.bus.post(SmartCardRemovedEvent(atr=prev_atr, reader=reader))
|
|
else:
|
|
self.logger.exception(e)
|
|
|
|
prev_atr = None
|
|
|
|
|
|
# vim:sw=4:ts=4:et:
|
|
|